Water repellant dehumidifier



April 25, 1967 v. D. MEIER WATER REPELLANT DEHUMIDIFIER Filed Oct. 23,1964 FIG. 1

INVENTOR. VINCENT D. MEIER F/GE wxhgveeaw ATTORNEY United States Patent3,315,447 WATER REPELLANT DEHUMIDIFIER Vincent D. Meier, PortWashington, N.Y., assignor to the Um'ted States of America asrepresented by the Secretary of the Navy Filed Oct. 23, 1964, Ser. No.406,205 2 Claims. (Cl. 55384) The present invention relates to a noveland improved container and more particularly to a novel and improvedcontainer in which a dehumidified environment may be maintained forprolonged periods of time.

In the preservation of items such as metallic hardware for prolongedstorage intervals, it is generally desirable to minimize deteriorationof various types including corrosion, mildew, fungus and othermicrobiological attacks. Inasmuch as the presence of moisture isgenerally necessary before any such deterioration can begin, varioustypes of packing materials and containers have been devised in the pastin an attempt to provide an effective vapor barrier about the item to beprotected. Heretofore, however, such attempts to control and dehumidifythe environment about the item to be protected in a practical andeconomically feasible manner have been at best only partiallysuccessful.

It is therefore a principal object of the present invention to provide anovel and improved protective package or container within which adehumidified atmosphere may be maintained for extended periods of time.

It is a further object of the present invention to provide a novel andimproved protective package or container which includes a membrane typeclosure through which gases and moisture vapor pass but through which nolarger particles including fungus spores, insects, corrosive dust andwater droplets may infiltrate.

It is a further object of the present inveniton to provide a novel andimproved protective package or container which includes a membrane typeclosure that on exposure to radiant solar energy permits the transfer ofmoisture outwardly from the interior of the package more readily than inthe opposite direction.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing wherein:

FIG. 1 of the drawing is a partially cutaway perspective view of apreferred embodiment of the present invention; and

FIG. 2 is a cross-sectional view of the embodiment of the inventionshown in FIG. 1 along reference line IIII therein.

A preferred embodiment of the invention is illustrated in FIGS. 1 and 2of the drawing. As shown therein, a moisture proof container having aclosure 3 is indicated at 5. Container 5, which is shown in one suitableform,

is a metallic drum having a cylindrical peripheral wall 7 and a bottom9. An opening at the top of container 5 for the insertion and removal ofits contents is of substantial size and is herein illustrated to extendacross the full diameter of the drum. Around the opening in container 5,the peripheral edge of wall 7 is preferably rolled outwardly anddownwardly into a hollow bead 11 of circular cross-section.

The closure 3 includes the perforated metallic plate or grid 13 which inits container sealing position extends across the entire opening at thetop of container 5 and extends downwardly as at 15 at its outer edge toresiliently engage the bead 11 on container 5. Two flexible permeablemembranes 17 and 19 are disposed on opposite sides of plate 13 and arepreferably secured to the plate in any 3,315,447 Patented Apr. 25, 1967suitable manner adjacent its outer downwardly flanged edge. Otherwise,the membranes 17 and 19 are unattached to the plate 13 and generallyform pockets that respectively bellow above and below the plate 13. Eachpocket on either side of plate 13 is filled with a suitable hygroscopicmaterial 21 such as silica gel or lithium chloride. The outer membrane17 which forms the pocket above plate 13 is preferably dark in color soas to absorb heat from solar radiant energy in a manner which will bedescribed more fully hereinafter. The inner membrane 19 which extendsdownwardly beneath plate 13 is preferably transparent or colorless.Otherwise, any suitable plasticized vinyl film which exhibits anincrease in porosity with an increase in temperature in a manner whichis described more fully hereinafter may be used to form membranes 17 and19.

In operation, the item to be protected is first placed in container 5and the closure 3 is resiliently secured over the head 11 on the upperlip of container 5. When during the heat of the day, solor energypenetrates closure 3 and warms the membranes 17 and 19, the desiccant21, and the atmosphere Within the container, the desiccant 21 tends todischarge moisture into the interior of container 5 as well as the outeratmosphere. However, inasmuch as the temperature of the atmospherewithin the container 5 rises more than that of the outside atmosphere,the internal moisture vapor pressure increases more than the moisturevapor pressure outside the container and more moisture from thedesiccant 21 is transmitted outwardly into the outer atmosphere thaninwardly into the interior of the container. Moreover, inasmuch asmembranes 17 and 19 become more porous with an increase in temperatureand inasmuch as the outer membrane 17 is dark in color and thereforeabsorbs more heat from the solar radiant energy than the colorless innermembrane 19, moisture from the desiccant 21 passes more readily into theouter ambient atmosphere than into the interior of container 5.

Later, at the end of the day when the sun goes down and the container 5and its contents begin to cool, the desiccant 21 tends to reabsorbmoisture from the interior of container 5 as well as from the outeratmosphere. The atmosphere within the container generally cools morethan the atmosphere outside so that the moisture vapor pressure insidecontainer 5 decreases more than that outside. Therefore, there is atendency during the cooling interval for the desiccant 21 to absorb moremoisture from the outer atmosphere than from the interior of container5. However, at the same time outer membrane 17 cools faster than innermembrane 19 causing outer membrane 17 to be less porous than innermembrane 19. There is therefore a simultaneous counter tendency of thedesiccant to absorb more moisture from the interior of container 5during the cooling interval. Thus, it will be seen that the net effectof the intermittent exposure of container 5 to solar energy is tomaintain a relatively dehumidified atmosphere within container 5 forextended periods of time without a need of replacing the desiccant 21which otherwise might be expected to become moisture saturated.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A closure for an enlarged opening in a container, said closurecomprising:

(a) a first plasticized vinyl membrane which covers the entire openingand is sealed to the lip of the container that defines the opening;

- e the exterior surface of said first membrane and is also sealed tothe lip of the container, said second membrane being dark in color so asto readily absorb heat from radiant solar energy; and

(c) a desiccant disposed between the first and second membranes. 7

2. A closure for an enlarged opening in a container, said closurecomprising:

(a) a perforated plate disposed across the opening in the container; 7

(b) a first plasticized vinyl membrane which covers the entire interiorsurface of the plate;

(0) a second plasticized' vinyl membrane which covers the entireexterior surface of the plate, said second membrane being dark in colorso as to readily absorb heat from radiant solar energy; and

(d) a desiccant disposed between the plate and both said membranes.

References Cited by the Examiner UNITED STATES PATENTS Poetschke 55 -3ssX FOREIGN PATENTS Great Britain.

REUBEN FRIEDMAN, Primary Examiner.

J. W. ADEE, Assistant Examiner.

1. A CLOSURE FOR AN ENLARGED OPENING IN A CONTAINER, SAID CLOSURECOMPRISING: (A) A FIRST PLASTICIZED VINYL MEMBRANE WHICH COVERS THEENTIRE OPENING AND IS SEALED TO THE LIP OF THE CONTAINER THAT DEFINESTHE OPENING; (B) A SECOND PLASTICIZED VINYL MEMBRANE WHICH COVERS THEEXTERIOR SURFACE OF SAID FIRST MEMBRANE AND IS ALSO SEALED TO THE LIP OFTHE CONTAINER, SAID SECOND MEMBRANE BEING DARK IN COLOR SO AS TO READILYABSORB HEAT FROM RADIANT SOLAR ENERGY; AND (C) A DESICCANT DISPOSEDBETWEEN THE FIRST AND SECOND MEMBRANES.